SAN DIEGO — Improving health of critical starters today helped soothe the lingering wounds of a rotation that is shoving the Rockies toward the bottom of the National League West.

Opening day starter Jeremy Guthrie threw to hitters at Petco Park and experienced no issues with the AC joint in his shoulder. He said it went well and head athletic trainer Keith Dugger said Guthrie looked “fabulous.” Guthrie will make a rehab start Thursday — it’s likely the only one he will require before rejoining the rotation — either for Class-A Modesto or Triple-A Colorado Springs.

“I have heard the team setback used. There have been no setbacks. It’s been making progress. And there was no pain,” Guthrie said.

Drew Pomeranz has a purple bruise above his right knee from where a line drive struck him, but his leg already feels better than Monday night when he exited with a pronounced limp after just three innings. Pomeranz believes he will be able to make his next start, though it’s possible with the off day the Rockies could push him back a few days.

“It’s better than I expected. It’s not nearly as stiff,” Pomeranz said.

Jorge De La Rosa was unhappy with his performance Monday night for Modesto, reaching only 68 pitches because of a long inning. His curveball showed improvement, and he again reached 93 mph on his fastball. De La Rosa will throw a bullpen Wednesday in San Diego and is scheduled to pitch in Tulsa on Saturday. The mapped out plan calls for a pair of starts in Double-A and Triple-A before joining the Rockies.

“I want to get back here and help. It’s hard to watch when I know they are struggling,” De La Rosa said.

Left-hander Christian Friedrich will make his big league debut Wednesday against the Padres. He credited his physical transformation — he dropped more than 30 pounds — and renewed positive attitude for his ascension this season. The former 2008 first-round pick was largely disappointing the past two years because of injuries and ineffectiveness. He made a commitment to change this offseason. Not only does he look different, but he gleaned confidence from advice given to him by veteran pitchers Mike Hampton, Jamie Moyer and Cliff Lee.

“You don’t realize how much you say words like can’t. I just don’t have doubt anymore,” Friedrich said. “I am not reacting to what the hitter does anymore. I want the hitters to react to me.”

Patrick, a third-generation Colorado native, is back for his second stint covering the Rockies. He first covered the team from 2005-2009, helping chronicle “Rocktober” in 2007 and also following the team’s playoff run in 2009.

Nick Groke has worked at The Denver Post since 1997, as a sports reporter, city reporter, entertainment writer and digital editor and producer, among other newsroom posts. He also writes regularly about boxing, soccer, MMA and NASCAR.